Iran Is Blowing Maritime Law Out of the Water

In the war between Iran and the joint force of the US and Israel, the Islamic Republic’s strongest tactic is to obstruct shipping in its coastal Strait of Hormuz.

The regime has strangled the world’s supply of oil and natural gas by attacking several commercial vessels as they transited the Persian Gulf channel. Some of Iran’s naval weapons have killed members of the ships’ crews.

As a political matter, Iran hopes that creating a global energy crisis will generate opposition to the US-Israeli military campaign. But as a legal matter, Iran’s targeting of civilian ships is a flagrant violation of international law.

Article 16(4) of the 1958 Geneva Convention on the Territorial Sea prohibits “the suspension of the innocent passage of foreign ships through straits” such as the Strait of Hormuz. Iran signed the 1958 document, as well as an updated version of the treaty, the 1982 United Nations Convention for the Law of the Sea.

The regime never “ratified” either treaty because it did not incorporate the international laws into its domestic law. That means Iran never became a formal party to the two pacts. However, the “innocent passage” framework of at least the 1958 convention is considered legally binding on Iran through customary international law, a consequence of widespread maritime practice.

The United Nations Security Council applied the principle of innocent passage during the Iran-Iraq War of the 1980s. The council rebuked both combatants for firing on commercial oil tankers in the Persian Gulf.

In the current war, the UN Security Council likewise chided Iran’s lethal interference with civilian shipping in the Strait of Hormuz. A coalition of 22 countries including two Arab Gulf states recently signed a joint statement that condemned Iran’s violent closure of the strait and warned of “appropriate efforts” to reopen it. A US military contingent is now headed to the strait, presumably to clear the key coastal terrain.

Iran attempts to evade its maritime obligations with two legal arguments.

First, it asserts self-styled “maritime claims,” in which every commercial ship’s right of innocent passage through the Strait of Hormuz is subject to the regime’s “prior approval.” Iran accordingly grants safe passage to vessels from “friendly” states like China and Pakistan but not ships that could “benefit the aggressors.”

Assuming an additional power of prior approval, Iran has threatened to impose toll charges on ships passing through the waterway. International maritime organizations such as the United Kingdom Maritime Operations Center have confirmed that Iran’s self-serving legal concoction is unfounded. In fact, most of the shipping lanes in the strait run through the territorial waters of Oman, which lie beyond Iran’s legal reach.

Iran alternately contends that its anti-shipping terrorism in the strait is a “tool of pressure” to combat the US and Israel, implying a right of military self-defense. But the laws of naval warfare do not permit attacks on ordinary civilian vessels as a means of self-defense.

Finding Iran in breach of maritime law is easy. Enforcing the law is another matter.

The International Court of Justice cannot assert jurisdiction over a state without that state’s consent. The International Criminal Court lacks authority over Iran because the state never signed the court’s enabling treaty. The Security Council could vote on Bahrain’s proposed March 23, 2026, resolution authorizing “all necessary means” to reopen the Strait of Hormuz. But the measure would probably be vetoed by Russia and/or China, states that oppose the use of force against Iran.

At stake is nothing less than freedom of navigation, which is vital to global trade and security. If Iran can paralyze the Strait of Hormuz, other nations may block similar chokepoints such as the Strait of Taiwan, the Turkish Straits, the Panama Canal, or the Suez Canal. The resulting chaos could render maritime law a dead letter.

It may be difficult for American-Israeli warfare to release Iran’s illegal grip on the Strait of Hormuz. Nevertheless, military action may be the only way to restore the rule of law in the waterway and deter future maritime aggressions.

Joel M. Margolis is the legal commentator of the American Association of Jewish Lawyers and Jurists, US Affiliate of the International Association of Jewish Lawyers and Jurists. He is the author of The Israeli-Palestinian Legal War.